Replace additional unsafe string functions

src/Platform.c

@@ -411,6 +411,40 @@ uint64_t PltGetMillis(void) {
 #endif
 }
 
+bool PltSafeStrcpy(char* dest, size_t dest_size, const char* src) {
+    LC_ASSERT(dest_size > 0);
+
+#ifdef LC_DEBUG
+    // In debug builds, do the same little trick that MSVC
+    // does to ensure the entire buffer is writable.
+    memset(dest, 0xFE, dest_size);
+#endif
+
+#ifdef _MSC_VER
+    // strncpy_s() with _TRUNCATE does what we need for MSVC.
+    // We use this rather than strcpy_s() because we don't want
+    // the invalid parameter handler invoked upon failure.
+    if (strncpy_s(dest, dest_size, src, _TRUNCATE) != 0) {
+        LC_ASSERT(false);
+        dest[0] = 0;
+        return false;
+    }
+#else
+    // Check length of the source and destination strings before
+    // the strcpy() call. Set destination to an empty string if
+    // the source string doesn't fit in the destination.
+    if (strlen(src) >= dest_size) {
+        LC_ASSERT(false);
+        dest[0] = 0;
+        return false;
+    }
+
+    strcpy(dest, src);
+#endif
+
+    return true;
+}
+
 int initializePlatform(void) {
     int err;
 

src/Platform.h

@@ -128,3 +128,4 @@ int initializePlatform(void);
 void cleanupPlatform(void);
 
 uint64_t PltGetMillis(void);
+bool PltSafeStrcpy(char* dest, size_t dest_size, const char* src);

src/PlatformSockets.c

@@ -33,7 +33,7 @@ DWORD (WINAPI *pfnWlanSetInterface)(HANDLE hClientHandle, CONST GUID *pInterface
 
 #endif
 
-void addrToUrlSafeString(struct sockaddr_storage* addr, char* string)
+void addrToUrlSafeString(struct sockaddr_storage* addr, char* string, size_t stringLength)
 {
     char addrstr[URLSAFESTRING_LEN];
 
@@ -43,7 +43,7 @@ void addrToUrlSafeString(struct sockaddr_storage* addr, char* string)
         inet_ntop(addr->ss_family, &sin6->sin6_addr, addrstr, sizeof(addrstr));
 
         // IPv6 addresses need to be enclosed in brackets for URLs
-        sprintf(string, "[%s]", addrstr);
+        snprintf(string, stringLength, "[%s]", addrstr);
     }
     else
 #endif
@@ -52,7 +52,7 @@ void addrToUrlSafeString(struct sockaddr_storage* addr, char* string)
         inet_ntop(addr->ss_family, &sin->sin_addr, addrstr, sizeof(addrstr));
 
         // IPv4 addresses are returned without changes
-        sprintf(string, "%s", addrstr);
+        snprintf(string, stringLength, "%s", addrstr);
     }
 }
 

src/PlatformSockets.h

@@ -82,7 +82,7 @@ typedef struct sockaddr_in LC_SOCKADDR;
 #else
 #define URLSAFESTRING_LEN INET_ADDRSTRLEN
 #endif
-void addrToUrlSafeString(struct sockaddr_storage* addr, char* string);
+void addrToUrlSafeString(struct sockaddr_storage* addr, char* string, size_t stringLength);
 
 SOCKET createSocket(int addressFamily, int socketType, int protocol, bool nonBlocking);
 SOCKET connectTcpSocket(struct sockaddr_storage* dstaddr, SOCKADDR_LEN addrlen, unsigned short port, int timeoutSec);

src/RtspConnection.c

@@ -72,8 +72,8 @@ static bool initializeRtspRequest(PRTSP_MESSAGE msg, char* command, char* target
     createRtspRequest(msg, NULL, 0, command, target, "RTSP/1.0",
         0, NULL, NULL, 0);
 
-    sprintf(sequenceNumberStr, "%d", currentSeqNumber++);
-    sprintf(clientVersionStr, "%d", rtspClientVersion);
+    snprintf(sequenceNumberStr, sizeof(sequenceNumberStr), "%d", currentSeqNumber++);
+    snprintf(clientVersionStr, sizeof(clientVersionStr), "%d", rtspClientVersion);
     if (!addOption(msg, "CSeq", sequenceNumberStr) ||
         !addOption(msg, "X-GS-ClientVersion", clientVersionStr) ||
         (!useEnet && !addOption(msg, "Host", urlAddr))) {
@@ -478,7 +478,7 @@ static bool sendVideoAnnounce(PRTSP_MESSAGE response, int* error) {
         request.flags |= FLAG_ALLOCATED_PAYLOAD;
         request.payloadLength = payloadLength;
 
-        sprintf(payloadLengthStr, "%d", payloadLength);
+        snprintf(payloadLengthStr, sizeof(payloadLengthStr), "%d", payloadLength);
         if (!addOption(&request, "Content-length", payloadLengthStr)) {
             goto FreeMessage;
         }
@@ -582,7 +582,7 @@ static int parseOpusConfigurations(PRTSP_MESSAGE response) {
         channelCount = CHANNEL_COUNT_FROM_AUDIO_CONFIGURATION(StreamConfig.audioConfiguration);
 
         // Find the correct audio parameter value
-        sprintf(paramsPrefix, "a=fmtp:97 surround-params=%d", channelCount);
+        snprintf(paramsPrefix, sizeof(paramsPrefix), "a=fmtp:97 surround-params=%d", channelCount);
         paramStart = strstr(response->payload, paramsPrefix);
         if (paramStart) {
             // Skip the prefix
@@ -801,12 +801,12 @@ int performRtspHandshake(PSERVER_INFORMATION serverInfo) {
             // NB: If the remote address is not a LAN address, the host will likely not enable high quality
             // audio since it only does that for local streaming normally. We can avoid this limitation,
             // but only if the caller gave us the RTSP session URL that it received from the host during launch.
-            addrToUrlSafeString(&RemoteAddr, urlAddr);
+            addrToUrlSafeString(&RemoteAddr, urlAddr, sizeof(urlAddr));
             sprintf(rtspTargetUrl, "rtsp%s://%s:%u", useEnet ? "ru" : "", urlAddr, RtspPortNumber);
         }
     }
     else {
-        strcpy(urlAddr, "0.0.0.0");
+        PltSafeStrcpy(urlAddr, sizeof(urlAddr), "0.0.0.0");
         sprintf(rtspTargetUrl, "rtsp%s://%s:%u", useEnet ? "ru" : "", urlAddr, RtspPortNumber);
     }
 

src/SdpGenerator.c

@@ -91,10 +91,13 @@ static int addAttributeBinary(PSDP_OPTION* head, char* name, const void* payload
         return -1;
     }
 
+    if (!PltSafeStrcpy(option->name, sizeof(option->name), name)) {
+        free(option);
+        return -1;
+    }
+
     option->next = NULL;
     option->payloadLen = payloadLen;
-    strncpy(option->name, name, sizeof(option->name));
-    option->name[sizeof(option->name) - 1] = '\0';
     option->payload = (void*)(option + 1);
     memcpy(option->payload, payload, payloadLen);
 
@@ -525,7 +528,7 @@ char* getSdpPayloadForStreamConfig(int rtspClientVersion, int* length) {
     char* payload;
     char urlSafeAddr[URLSAFESTRING_LEN];
 
-    addrToUrlSafeString(&RemoteAddr, urlSafeAddr);
+    addrToUrlSafeString(&RemoteAddr, urlSafeAddr, sizeof(urlSafeAddr));
 
     attributeList = getAttributesList(urlSafeAddr);
     if (attributeList == NULL) {

src/SimpleStun.c

@@ -65,7 +65,7 @@ int LiFindExternalAddressIP4(const char* stunServer, unsigned short stunPort, un
     hints.ai_protocol = IPPROTO_UDP;
     hints.ai_flags = AI_ADDRCONFIG;
 
-    sprintf(stunPortStr, "%u", stunPort);
+    snprintf(stunPortStr, sizeof(stunPortStr), "%u", stunPort);
     err = getaddrinfo(stunServer, stunPortStr, &hints, &stunAddrs);
     if (err != 0 || stunAddrs == NULL) {
         Limelog("Failed to resolve STUN server: %d\n", err);